WASHINGTON (Reuters) - A new analysis of data from a key prostate cancer study has strengthened the view that a drug that is now sold as a generic may be a valuable weapon to prevent prostate cancer, researchers said on Monday.
The drug is finasteride, formerly sold by Merck and Co as Proscar to treat enlargement of the prostate and now available generically. The drug affects male hormone levels.
The men in the study were taking the drug in a dose of 5 milligrams. In a one milligram dose, finasteride is sold by Merck as the baldness remedy Propecia.
The initial results of the study were announced in 2003.
The extensive re-analysis of the data showed that finasteride reduced a man's risk for developing prostate cancer by about 30 percent, the researchers said. That compares to the initial finding that it reduces the risk by about 25 percent.
When the initial results of the study were announced, the researchers cautioned that men in the study who developed prostate cancer while taking finasteride were more likely to have high-grade cancers, which may spread quickly even if the tumors are small.
But the new analysis showed finasteride did not induce aggressive cancers and may reduce the risk of these high-grade tumors, said Dr. Ian Thompson of the University of Texas Health Sciences Center at San Antonio, who led the original study and was involved in reassessing the data.
The researchers also concluded the cancer cases finasteride prevented in the trial were "clinically significant" in that they were the same type that currently are treated with radiation and surgical removal of the prostate gland.
SCREENING TEST
Many men in the United States and some other countries use the prostate-specific antigen, or PSA, blood test to screen for prostate cancer. PSA is a substance produced by the prostate gland that in a high level may indicate prostate cancer.
"Conceivably, every man when he turns 55, if prostate cancer is of concern to him -- if he's having the PSA checked on a regular basis -- his doctor probably should at least tell him that he can reduce his risk by about 30 percent by taking finasteride," Thompson said in a telephone interview.
